VintageVmax.com

I bought a 85 vmax this year and it back shifts (shifts out) at 7200 rpm. The belt is still about 1/2 inch from the top of the primary clutch when it shifts out. The engine just bogs out. I thinking it is clutching the carbs have been cleaned but when taken apart they was spotless very clean. The secondary clutch has a pink spring and a 45 spring set. The spring setting i used was c-2 and c-3. The belt is a new TMX1080 dayco. The primary clutch is a comet 217506A with yellow spring. I'am i thinking right by thinking it is in the clutching or ? I set the carbs by the factory setting book i even did it 3 times thinking i was missing some thing.
The secondary clutch is clean and in excellet shape. I was told the primary clutch has less than 50 miles on it and it looks like it.
Does anyone have any ideas on what i may be missing that is causing the problem?

Sounds like you are Running a 108 and a 1 1/4" belt ?

Lots of info..... viewtopic.php?f=2&t=1506

Yes from what I have found out. 108 with 1 1/4 belt. Is this the way it works with this set up? What can i do to change it to run out like it should? Iam new to this.

Very few if any two sleds are at the same state of tune, setup, conditions ect. please do a little reading on the many topics and posts in the link I posted on clutching especially, like this one viewtopic.php?t=23

try the yamaha 8m6 belt and replace your secondary spring. 3:16 (YAMMIE TONY)

We are making great progress with all the great info. This is what I have done. Clutch alignment checked was off just a little bit. I installed the blue with white polaris spring in the primary. Set the secondary spring in c-3. Installed a new yamaha8m6 belt. The needle jet is in the 3 position. And reset the carbs.The sled now engages at around 3800 rpm and boges down at around 8200 rpm when running full throttle. If i run up to 3/4 throttle it runs great but when I open it up to full throttle it boges down and will back shift out to 7200 rpm and at 3/4 throttle the belt runs up to about 1/4 inch from the top of the primary but at full throttle it runs up to 1/2 inch from the top. Runs better at 3/4 then at full throttle. I'am thinking the jetting is off. Should I start with changing the power jets or the main jets?

THANK YOU TO ALL FOR YOUR HELP

yeah sounds to me like your jetting is off some... what jets are in it? while your at it check the base gaskets for blowouts. mine suddenly ran like crap one night and didnt have anything at WOT, it was the base gaskets. i got real lucky, because i didnt know what the problem was and rode 10 or so miles home